The Light Fastness of Anthraquinone Disperse Dyes on Poly(ethylene terephthalate)

The I.S.O. light-fastness grades of thirty-two anthraquinone disperse dyes on polyester fabric have been determined. High light fastness is exhibited by the 1- and 1,4-hydroxy derivatives and 1- or 1,4-sub-stituted amino derivatives possessing N-substituted electron-withdrawing groups. The 1- and 2-methoxyanthraquinones, 2-hydroxyanthraquinones and all the 2-amino derivatives examined, on the other hand, have poor light fastness. The high light stability of the 1-hydroxy- and 1-anilinoanthraquinones may be due to rapid de-activation of their photo-excited singlet states, while the poor light fastness of the 2-aminoanthraquinones is probably due to their ability to abstract electrons from their environment.